CalDAV calendar remains stale and refresh spinner never finishes on /e/OS 4.2 and Fairphone 6

[care4hair]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

Fossify Calendar 1.10.3

Affected Android/Custom ROM version

/e/OS 4.2

Affected device model

Fairphone 6

How did you install the app?

F-Droid / IzzyOnDroid

Which calendar service or provider do you use, if any?

posteo.de (caldav)

Which sync adapter app do you use for calendar synchronization, if any?

Native /e/OS/ "Account Manager" which is a fork of DAVx5.

Steps to reproduce the bug

1. Configure a Posteo.de CalDAV account using the built-in /e/OS Account Manager.
2. Enable the relevant remote calendar for synchronization.
3. Confirm that the calendar is visible in both the native /e/OS Calendar app and Fossify Calendar.
4. Create a test event in the native /e/OS Calendar app.
5. Trigger a manual synchronization in the /e/OS Account Manager.
6. Confirm that the event appears on the Posteo.de server.
7. Confirm that the event appears in the native /e/OS Calendar app.
8. Check Fossify Calendar.
9. Create another test event in Fossify Calendar, explicitly selecting the same Posteo.de calendar.
10. Trigger another manual synchronization in the /e/OS Account Manager.
11. Check whether the Fossify-created event appears on the Posteo.de server.
12. Delete an event on the Posteo.de server or from another synchronized calendar client.
13. Synchronize again.
14. Check the native /e/OS Calendar app and Fossify Calendar.
15. In Fossify Calendar, pull down to refresh and wait several minutes.

Expected behavior

Fossify Calendar should remain consistent with the selected Posteo.de CalDAV calendar in both directions.

• Events created in Fossify should be uploaded to the selected remote calendar.
• Events created elsewhere and synchronized to the device should appear in Fossify.
• Events deleted on the server should disappear from Fossify.
• Pull-to-refresh should reload the current data and then finish.

Actual behavior

Fossify Calendar displays stale and incomplete data.

• An event created in the native /e/OS Calendar app is uploaded successfully to the Posteo.de server and appears in the native /e/OS Calendar app, but does not appear in Fossify.
• Some events created in Fossify do not appear on the Posteo.de server after synchronization.
• Events deleted on the Posteo.de server remain visible in Fossify.
• Pulling down to refresh starts a circular loading indicator that continues indefinitely for several minutes.
• The refresh does not update the displayed calendar data.

The calendar itself is visible in Fossify and older entries are displayed. The problem is that the displayed data is stale.

Screenshots/Screen recordings

No response

Additional information

This report is related to existing issues #270, #656/#1091, and #846, especially the reports concerning endless refresh loading and changes not being synchronized in either direction.

The current report adds the following observation: the native /e/OS Calendar app displays the current data correctly, while Fossify Calendar displays stale data. This suggests that the Posteo.de server synchronization and Android Calendar Provider contain current data, but Fossify is not correctly reading, refreshing, or writing the provider data.

The calendar worked correctly in Fossify in the past. The problem was first noticed in July 2026. Around that period, the device was updated from /e/OS 4.0 to /e/OS 4.1.1. So far this is just a timewise correlation not a causal chain. I cannot confirm whether the /e/OS update caused the regression. The device is currently running /e/OS 4.2.

Environment:

• Device: Fairphone 6
• Operating system: /e/OS 4.2
• Exact /e/OS build: [insert build number]
• Fossify Calendar: 1.10.3
• Installation source: F-Droid
• Calendar provider: Posteo.de CalDAV
• Sync adapter: built-in /e/OS Account Manager, based on DAVx⁵

Troubleshooting performed:

• Closed and reopened Fossify Calendar.
• Force-stopped Fossify Calendar.
• Manually triggered synchronization in the /e/OS Account Manager.
• Cleared Fossify's cache.
• Disabled and re-enabled the calendar in Fossify.
• Rebooted the device.

None of these actions changed the behavior.

No crash occurs. The main visible symptom during refresh is an indefinitely running loading indicator.

** This report was written with the help of AI but guided and reviewed by me! **

[care4hair]

I think this can be closed for now. I figured out that there was at least one crucial setting wrong. The relevant calendars where not activated under "Synchronisierte Kalendar" (German). I am pretty sure this was the case in the past. I have no explanation why they were deactivated. In any case I will close this item and only reopen it if I observe the issue with the corrected settings again.